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Abstract: Background: The relationship between the levels of gonadotropic hormones and bone metabolism-related cytokines in Chinese women is unclear. We investigated the relationship between FSH and LH and OPG, leptin, TGF-β1, and TGF-β2 in Chinese women. Methods: A cross-sectional study of 694 Chinese women, aged 20 to 82y was conducted. Levels of serum FSH, LH, OPG, leptin, TGF-β1, and TGF-β2 were determined. Results: In premenopausal females, serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels seemly showed no correlation with the cytokine levels. In perimenopausal females, serum FSH and LH levels showed significant positive correlation with osteoprotegerin (OPG) and transforming growth factor-β2 (TGF-β2) levels (r =0.286 to 0.405, all P =0.000), whereas they showed negative correlation with TGF-β1 levels (r =−0.413 and −0.354, all P =0.000). In postmenopausal females, FSH and LH levels showed positive correlation with OPG levels (r =0.247 and 0.241, all P =0.000), negative correlation with leptin and TGF-β1 levels (r =−0.234 to −0.319, all P =0.000), and no correlation with TGF-β2 levels. Multiple linear regression stepwise analysis revealed the following results. In premenopausal females, 2.0% and 1.5% of the changes in LH could be explained by OPG and leptin, respectively, while 1.9% of the changes in OPG could be explained by LH. In perimenopausal females, the determinants of OPG and TGF-β1 on FSH were 10.9% and 17.0%, respectively, and the determinants of OPG, TGF-β1 and TGF-β2 on LH were 4.5%, 4.9% and 16.4%, respectively. The determinants of FSH and LH on OPG were 14.5% and 2.5%, respectively. The determinant of FSH on TGF-β1 was 4.5%, while the determinant of LH on TGF-β2 was 16.4%. In postmenopausal females, the determinants of leptin and OPG on FSH were 10.2% and 2.8%, respectively, and the determinants of OPG and TGF-β1 on LH were 5.8% and 2.3%, respectively. The determinant of FSH on OPG, leptin and TGF-β1 were 6.1%, 3.4% and 9.2%. Conclusions: These results indicate that age-related gonadotropic hormone levels are associated with changes in OPG, TGF-β1, TGF-β2 and leptin, and change with menopausal status. [Copyright &y& Elsevier]

Abstract: Background: Adiponectin and leptin, as the main circulating peptides secreted by adipose tissue, are potential contributors to bone metabolism. However, their association with bone mineral density (BMD) is unknown. We investigated whether these serum adipocytokines concentrations are associated with BMD and bone turnover markers. Methods: Serum adiponectin, leptin concentrations, bone turnover biochemical markers, and BMD were determined in 265 premenopausal and 336 postmenopausal Chinese women. Results: In postmenopausal Chinese women, the multiple linear stepwise regression analysis showed that year since menopause, lean mass, estradiol, and adiponectin, but not fat mass, leptin, were independent predictors of BMD in postmenopausal Chinese women. However, in premenopausal Chinese women, adiponectin was not the predictor of BMD. The significant positive correlations between adiponectin and bone-specific alkaline phosphatase (BAP), bone cross-linked N-telopeptides of type I collagen (NTX) were found only in postmenopausal women. Serum BAP, and NTX, but not adiponectin, decreased in response to alendronate therapy. Conclusions: Adiponectin was an independent predictor of BMD, and positively correlated with bone turnover biochemical markers in postmenopausal Chinese women, but not premenopausal women. It suggested that adiponectin may exert a negative effect on bone mass by promoting excessive bone resorption associated with bone loss. However, these effects may be mediated by menopausal status. [Copyright &y& Elsevier]

Abstract: Background: Transforming growth factor-β 1 (TGF-β1), TGF-β2, osteoprotegerin (OPG), and leptin are important cytokines in the regulation of bone remodeling. We investigated the relationship of TGF-β1 and TGF-β2 concentrations with those of OPG and leptin in Chinese females. Methods: The serum concentrations of TGF-β1, TGF-β2, OPG, and leptin were measured by ELISA in 459 healthy Chinese females aged 25–80 y. Results: The mean values (±SD) of the serum concentrations of TGF-β1, TGF-β2, OPG, and leptin in Chinese females were 29.7±1.69 μg/l, 13.7±3.86 μg/l, 3.81±1.96 pmol/l, and 10.5±2.01 μg/l, respectively. Further, the serum TGF-β1 concentrations of postmenopausal women were significantly lower than those of perimenopausal and premenopausal women (24.3±1.59 vs 33.4±1.69 and 37.6±1.64, respectively), while the TGF-β2 concentrations of postmenopausal women were significantly higher than those of perimenopausal and premenopausal women (14.6±3.91 vs 13.5±3.93 and 11.7±2.68, respectively). The serum TGF-β1 concentration was found to be significantly negatively correlated with age (r =−0.335, P =0.000) and the TGF-β2 concentration, to be significantly positively correlated with age (r =0.230, P =0.000). The TGF-β1 concentration was found to be significantly negatively correlated with both TGF-β2 (r =−0.261, P =0.000) and OPG (r =−0.313, P =0.000) concentrations; a significantly positive correlation was found between the TGF-β1 and leptin concentrations (r =0.164, P =0.000) and between TGF-β2 and OPG concentrations (r =0.432, P =0.000). Conclusion: These results provide age-related reference values of TGF-β1 and TGF-β2 in Chinese adult women, and reveal the relationships between these cytokines. [Copyright &y& Elsevier]

Abstract: Background: Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) may play an important role in bone mass regulation in postmenopausal women. Methods: A cross-sectional study of 699 healthy Chinese women, aged 20 to 82 y, was conducted. Serum FSH and LH and BMD were measured at the posteroanterior (PA) spine, lateral spine, total hip, and distal forearm. Results: The geometric mean values (±SD) of serum FSH and LH in premenopausal women were 3.94±2.08 and 7.51±2.58 IU/l, respectively, and in postmenopausal women were 28.8±1.88 and 25.6±1.95 IU/l, respectively. The correlation of FSH to BMD at different skeletal regions (r =−0.597–−0.492, P =0.000) was higher than that of LH to BMD (r =−0.452–−0.332, P =0.000). The prevalences of osteoporosis for the quartiles of FSH at various skeletal sites were 0.57%, 0.43%, 27.1%, and 30.9%, respectively; and of LH were 2.14%, 4.43%, 19.5%, and 26.0%, respectively. The prevalence of osteoporosis in 3rd and 4th quartile was more significantly increased than the 1st and 2nd quartile. Conclusions: These data suggest that FSH and LH levels in circulation are associated with BMD changes and osteoporosis occurrence in Chinese women. [Copyright &y& Elsevier]

Abstract: Background: Osteoprotegerin (OPG) and leptin are important cellular factors in the regulation of bone remodeling. We investigated the serum OPG and leptin in Chinese women. Methods: The serum OPG and leptin in 690 Chinese women aged 20–81y were measured by an ELISA. The values of OPG and leptin in women of other races were acquired from previous reports on the same. Results: The geometric mean values (± SD) of the serum OPG and leptin in Chinese women were 3.42±1.91pmol/l and 10.5±1.99μg/l, respectively. Further, the serum OPG (4.39±1.85 vs 2.74±1.81) and leptin (11.4±2.21 vs 9.68±1.81) in postmenopausal women were significantly higher than in premenopausal women. The serum OPG in middle-aged Chinese women was significantly higher than that in middle-aged Austrian and Icelandic women; however, this is quite contrary to the results obtained in the case of old-aged women. The values of serum leptin in Chinese women were significantly lower than those in white, black, and Mexican American women. Conclusions: These results provide reliable reference values for OPG and leptin in Chinese adult women. The serum of OPG and leptin differ with ethnicity. [Copyright &y& Elsevier]